Adenosine receptors in brain membranes: Binding of N6-cyclohexyl[3H]adenosine and 1,3-diethyl-8-[3H]phenylxanthine

Abstract

N6-Cyclohexyl[3H]adenosine ([3H]CHA) and 1,3-diethyl-8-[3H]phenylxanthine ([3H]DPX) bind to adenosine receptors in brain membranes. The agonist [3H]CHA has high affinity in both bovine and guinea pig brain (Kd, 0.7 nM and 6 nM, respectively). [3H]CHA binding kinetics are slow (dissociation t1/2; 60 min); binding is much higher at 25°C than at 0°C and is inhibited by guanine nucleotides. Potencies of nucleosides and xanthines in competing for [3H]CHA sites indicate that specific binding is entirely to A1 adenosine receptors. In bovine brain, the antagonist [3H]DPX exhibits high-affinity binding (Kd, 5 nM) to the same A1 receptors that bind [3H]CHA. Binding kinetics are rapid (dissociation t1/2, 1 min), and binding is moderately higher at 0°C than at 25°C. In guinea pig brain, [3H]DPX binding has only moderate affinity (Kd, 50 nM), and about 60% of specific binding is to sites that resemble A2 adenosine receptors.

title = "Adenosine receptors in brain membranes: Binding of N6-cyclohexyl[3H]adenosine and 1,3-diethyl-8-[3H]phenylxanthine",

abstract = "N6-Cyclohexyl[3H]adenosine ([3H]CHA) and 1,3-diethyl-8-[3H]phenylxanthine ([3H]DPX) bind to adenosine receptors in brain membranes. The agonist [3H]CHA has high affinity in both bovine and guinea pig brain (Kd, 0.7 nM and 6 nM, respectively). [3H]CHA binding kinetics are slow (dissociation t1/2; 60 min); binding is much higher at 25°C than at 0°C and is inhibited by guanine nucleotides. Potencies of nucleosides and xanthines in competing for [3H]CHA sites indicate that specific binding is entirely to A1 adenosine receptors. In bovine brain, the antagonist [3H]DPX exhibits high-affinity binding (Kd, 5 nM) to the same A1 receptors that bind [3H]CHA. Binding kinetics are rapid (dissociation t1/2, 1 min), and binding is moderately higher at 0°C than at 25°C. In guinea pig brain, [3H]DPX binding has only moderate affinity (Kd, 50 nM), and about 60% of specific binding is to sites that resemble A2 adenosine receptors.",

author = "Bruns, {R. F.} and Daly, {J. W.} and Snyder, {S. H.}",

year = "1980",

month = dec

day = "1",

language = "English (US)",

volume = "77",

pages = "5547--5551",

journal = "Proceedings of the National Academy of Sciences of the United States of America",

N2 - N6-Cyclohexyl[3H]adenosine ([3H]CHA) and 1,3-diethyl-8-[3H]phenylxanthine ([3H]DPX) bind to adenosine receptors in brain membranes. The agonist [3H]CHA has high affinity in both bovine and guinea pig brain (Kd, 0.7 nM and 6 nM, respectively). [3H]CHA binding kinetics are slow (dissociation t1/2; 60 min); binding is much higher at 25°C than at 0°C and is inhibited by guanine nucleotides. Potencies of nucleosides and xanthines in competing for [3H]CHA sites indicate that specific binding is entirely to A1 adenosine receptors. In bovine brain, the antagonist [3H]DPX exhibits high-affinity binding (Kd, 5 nM) to the same A1 receptors that bind [3H]CHA. Binding kinetics are rapid (dissociation t1/2, 1 min), and binding is moderately higher at 0°C than at 25°C. In guinea pig brain, [3H]DPX binding has only moderate affinity (Kd, 50 nM), and about 60% of specific binding is to sites that resemble A2 adenosine receptors.

AB - N6-Cyclohexyl[3H]adenosine ([3H]CHA) and 1,3-diethyl-8-[3H]phenylxanthine ([3H]DPX) bind to adenosine receptors in brain membranes. The agonist [3H]CHA has high affinity in both bovine and guinea pig brain (Kd, 0.7 nM and 6 nM, respectively). [3H]CHA binding kinetics are slow (dissociation t1/2; 60 min); binding is much higher at 25°C than at 0°C and is inhibited by guanine nucleotides. Potencies of nucleosides and xanthines in competing for [3H]CHA sites indicate that specific binding is entirely to A1 adenosine receptors. In bovine brain, the antagonist [3H]DPX exhibits high-affinity binding (Kd, 5 nM) to the same A1 receptors that bind [3H]CHA. Binding kinetics are rapid (dissociation t1/2, 1 min), and binding is moderately higher at 0°C than at 25°C. In guinea pig brain, [3H]DPX binding has only moderate affinity (Kd, 50 nM), and about 60% of specific binding is to sites that resemble A2 adenosine receptors.